The field of this invention is air distribution systems, and more particularly air handling units for air distribution systems for multiple story buildings.
Conventional air distribution systems for buildings typically include an air handling unit having discrete functional elements coupled together in series at a central location in the building. By way of example, such a unit might include an input plenum for mixing outside and return air, a filter bank, a conditioner unit (for heating and cooling), an airflow silencer, a fan and an output silencer. Generally, the various units are provided with rectangular cross-section geometry and outer packaging.
In multiple story building applications, a horizontal interconnection of all of these discrete elements typically requires relatively large space on a floor, and also requires a high velocity (and hence lossy) elbow interconnection between the output silencer and the vertical main distribution duct of the system. For air handling units having vertical interconnection of the discrete elements, a multiple story housing is typically required.
In addition to the relatively large space requirements for conventional systems, the various units impose severe floor loading constraints. There are also restrictive fan power constraints (due to relatively high losses in the silencers and through elbow connections). The serial combination of elements, interspersed with conventional silencers, requires several high-to-low and low-to-high air velocity changes. Such configurations have relatively high energy requirements for achieving the velocity control. Furthermore, the dispersed element configuration establishes a correspondingly dispersed source of noise, particularly in view of the generally rectangular geometry typically used for the various elements. In addition, each of the elements provide acoustical paths for transmission of noise to the rest of the building.
In typical applications, the conventional systems may be roof mounted, with each of the series-connected units having relatively large rectangular cross-section enclosures, and separate access doors for servicing. In severe weather environments, such systems are difficult to service, due to the number of separate elements which must be accessed, and the relatively large area in which the elements are dispersed.
It is an object of the present invention to provide an energy efficient air handling unit.
Another object is to provide a space efficient air handling unit.
Still another object is to provide an air distribution system with improved silencing characteristics.